The pharmacology of blinatumomab: state of the art on pharmacodynamics, pharmacokinetics, adverse drug reactions and evaluation in clinical trials

Therapeutic drug monitoring in acute lymphoblastic leukemia-a deep dive into pharmacokinetics, -dynamics, and -genetics of antileukemic drugs

INTRODUCTION

Therapeutic drug monitoring (TDM) is important to optimize drug exposure and minimize toxicity for the individual patient.

AREAS COVERED

This narrative review covers the pharmacokinetics (PK), -dynamics (PD) and -genetics of classic chemotherapeutic drugs used in frontline therapy for acute lymphoblastic leukemia (ALL), including anthracyclines, asparaginase, busulfan, cyclophosphamide, cytarabine, glucocorticoids, methotrexate, nelarabine, thiopurines, tyrosine kinase inhibitors, and vincristine. Furthermore, novel immunotherapies including blinatumomab, inotuzumab ozogamicin, and chimeric antigen receptor T-cells that are rapidly moving into frontline therapy are addressed. This review focuses on TDM already used in clinical practice as well as the unused potential and feasibility of TDM. Finally, important factors affecting PK/PD such as obesity and transition to adolescence and young adulthood are discussed.

EXPERT OPINION

Investigation of TDM as standard of care for antileukemic agents is highly warranted to personalize curative yet toxic anticancer regimens within frontline ALL treatment. Some of the drugs have been used in ALL treatment regimens for decades, but a wide range of new compounds are being introduced, some like blinatumomab reaching standard-of-care designation. Not least, optimized drug efficacy and reduction of the risk of serious toxicities may render TDM implementation cost-effective.

High-Throughput Centrifuge Force Microscopy Reveals Dynamic Immune-Cell Avidity at the Single-Cell Level

Cell-cell binding, mediated by the physical interactions of receptors and their ligands, plays a fundamental role in immune processes such as immune surveillance and T-cell activation. However, current approaches for measuring cell avidity often lack either throughput or quantitative precision. Here, we introduce a high-throughput approach for quantifying cell binding lifetimes and strength using a centrifuge force microscope (CFM)-a compact microscope operating within a standard benchtop centrifuge. The CFM enables live monitoring of single-cell interactions under force, conducting thousands of force experiments in parallel. To facilitate the real-time study of live cell interactions, we developed a next-generation CFM with multichannel fluorescence imaging capabilities. This system accommodates measurements in two modes: cell-protein binding and cell-cell avidity assays. Using this system, we investigated immune-cell binding mediated by Bispecific T-cell Engager (BiTE) molecules, a novel immunotherapy designed to enhance immune-cell targeting of cancer cells. In cell-protein assays, we quantified T- and B-cell unbinding from BiTE-functionalized surfaces, revealing receptor-specific relationships between ligand concentration and binding strength. In cell-cell assays, we examined BiTE-mediated binding of T-cells to Nalm6 B-cells, a precursor leukemia cell line, uncovering a strong, time-dependent increase in BiTE-mediated immune-cell avidity. By integrating high-throughput and quantitative single-cell force analysis, the CFM provides new insights into the dynamic nature of immunological interactions under force, with broad implications for immunotherapy and cellular mechanics.

A real-world pharmacovigilance study of blinatumomab based on the FDA adverse event reporting system

BACKGROUND

Blinatumomab, the first CD3/CD19 bispecific antibody, is FDA-approved for relapsed or refractory precursor B-cell acute lymphoblastic leukemia in adults and children. This study evaluates its safety profile through pharmacovigilance analysis of adverse events (AEs) reported in the FDA Adverse Event Reporting System (FAERS).

METHOD

We conducted a disproportionality analysis using four algorithms: Reporting Odds Ratio (ROR), Proportional Reporting Ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Item Gamma Poisson Shrinker (MGPS). Data from 2014Q1 to 2023Q4 were analyzed to identify safety signals related to blinatumomab, along with a stratification analysis to examine AE onset timing.

RESULT

A total of 17,131 AE reports were retrieved from the FAERS database, with 6,266 indicating blinatumomab as the primary suspect. We identified 277 preferred terms (PTs) demonstrating significant disproportionality across all algorithms. Notably, unexpected AEs included Graft Versus Host Disease, myelosuppression, and hypokalaemia. Common AEs were consistent across gender and age groups, predominantly occurring within one month of treatment.

CONCLUSION

This pharmacovigilance study utilizing the FAERS database identified potential AE signals associated with blinatumomab, providing essential insights for its safe clinical use.

Adverse events in the nervous system associated with blinatumomab: a real-world study

BACKGROUND

Nervous system toxicity (NST) is a frequent and serious adverse event (AE) associated with blinatumomab, the first bispecific antibody drug targeting CD19 and CD3. Real-world data are needed to better understand the incidence and characteristics of NST in clinical practice.

METHODS

Data were obtained from the FDA Adverse Event Reporting System (FAERS). The reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian confidence interval progressive neural network (BCPNN), and multi-item gamma Poisson shrinker (MGPS) algorithms were utilized for data mining.

RESULTS

A total of 5,962 blinatumomab-related cases were analyzed. NSTs were more frequent in males (44.01%) and younger individuals (18-45 years, 28.39%), with a higher prevalence in the USA (77.99%). Forty-three signals of NST were identified, of which neurotoxicity, neurological symptoms, agnosia, intention tremor, and immune effector cell-associated neurotoxicity syndrome had the highest ROR values. Concomitant use of medication for age, musculoskeletal system, genitourinary system, and sexual hormones were independent risk factors for NST, and age was an independent protective factor for fatal NST. The median time to onset (TTO) for neurological events was 3 days (range, 1 ~ 21). The highest fatality rate for neurological events was observed for increased intracranial pressure disorders, which also had the highest co-occurrence rate with cytokine release syndrome (CRS).

CONCLUSIONS

Age is an independent protective factor for fatal NST, and CRS leads to a higher fatality rate for NST patients treated with blinatumomab. Thorough medication evaluation should be conducted before administering blinatumomab, especially for high-risk patients with preexisting neurological conditions.

Efficacy of bortezomib combined with Hyper-CVAD in adults with relapsed acute lymphoblastic leukemia or positive measurable residual disease; effect of bortezomib in leukemia

PURPOSE

Despite advances in the treatment of adult acute lymphoblastic leukemia (ALL), relapse remains the most significant challenge in improving prognosis. Measurable residual disease (MRD) assessment can predict bone marrow relapse based on MRD positivity. As access to innovative therapies remains limited because of the high cost, chemotherapy is the widely utilized treatment option. The efficacy of a combination of bortezomib and Hyper-CVAD has been reported in patients with multiple myeloma; however, its efficacy has not yet been confirmed in patients with ALL.

METHODS

This prospective cohort study involved patients with ALL who presented with MRD-positive results or relapse and received treatment with a combination of bortezomib and Hyper-CVAD at two reference centers in Mexico City.

RESULTS

Of the 20 patients with positive MRD included in this study, 60% (n = 12) exhibited MRD negative results after combination treatment, 30% (n = 6) persisted positive MRD results, and 10% (n = 2) passed away. Of the 23 patients with bone marrow relapse, 43.5% (n = 10) achieved a second complete remission (2CR), 34.8% (n = 6) exhibited refractory status, and 21.7% (n = 5) passed away. To achieve a 2CR, 20% (n = 2) patients required less than four cycles of treatment, 50% (n = 5) required four cycles (two A and B cycles each), and 30% (n = 3) required six cycles.

CONCLUSION

The combination of bortezomib and Hyper-CVAD treatment exhibited better results in achieving MRD negative results, indicating its potential as a promising first-line treatment strategy for ALL.

Bispecific antibodies for the treatment of hematologic malignancies: The magic is T-cell redirection

Bispecific antibody therapy has revolutionized the treatment of hematologic malignancies. There are currently 7 FDA approved products with 4 different targets covering 5 indications in 4 diseases. Products include blinatumomab targeting B-cell ALL in MRD detectable first remission and in relapsed and/or refractory disease, elranatamab and teclistamab targeting BCMA in relapsed/refractory multiple myeloma, talquetamab targeting GPCR5D in multiple myeloma, and mosunetuzumab, epcoritamab and glofitamab which all target CD20 in follicular lymphoma, both follicular and large B cell lymphoma, or large B cell lymphoma alone, respectively. Each product utilizes the strategy of T-cell redirection by binding CD3 on the effector cell to target immune cells toward a tumor associated antigen. There are overlapping toxicities related to activation of the immune system and inflammation. The role of these agents in earlier lines of therapy and in novel combinations are under heavy investigation and their full utility and benefit in the treatment of hematologic malignancies is yet to be fully realized.

Rapid Systematic Screening of Bispecific Antibody Surrogate Geometries for T-Cell Engagement Using DNA Nanotechnology

Bispecific antibodies (bsAbs) are emerging immune-therapeutics, and many formats exist that differ considerably in structure. However, little systematic data exist about how the spatial organization of their components influences activity, requiring innovative approaches combining empirical and quantitative frameworks. This study presents a modular DNA nanotechnology platform to generate numerous bsAbs with surrogate geometries that span the structural features of the BiTE, IgG-like, and IgG-conjugate platforms to screen for T-cell engagement. Results highlight interesting structure-activity relationships regarding bsAb potency and selectivity and raise questions regarding the molecular phenomena underlying activity. To elucidate some effects, the platform was paired with a simple mathematical model. This work is thus one of the first to systematically investigate and reveal the importance of the spatial organization of bsAb components on activity and equally provides an accessible and convenient tool for rapidly mapping out such trends for other combinations of target epitopes.

Therapeutic antibodies in oncology: an immunopharmacological overview

The biotechnological development of monoclonal antibodies and their immunotherapeutic use in oncology have grown exponentially in the last decade, becoming the first-line therapy for some types of cancer. Their mechanism of action is based on the ability to regulate the immune system or by interacting with targets that are either overexpressed in tumor cells, released into the extracellular milieu or involved in processes that favor tumor growth. In addition, the intrinsic characteristics of each subclass of antibodies provide specific effector functions against the tumor by activating antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis, among other mechanisms. The rational design and engineering of monoclonal antibodies have improved their pharmacokinetic and pharmacodynamic features, thus optimizing the therapeutic regimens administered to cancer patients and improving their clinical outcomes. The selection of the immunoglobulin G subclass, modifications to its crystallizable region (Fc), and conjugation of radioactive substances or antineoplastic drugs may all improve the antitumor effects of therapeutic antibodies. This review aims to provide insights into the immunological and pharmacological aspects of therapeutic antibodies used in oncology, with a rational approach at molecular modifications that can be introduced into these biological tools, improving their efficacy in the treatment of cancer.

Next-Generation Therapeutic Antibodies for Cancer Treatment: Advancements, Applications, and Challenges

The field of cancer treatment has evolved significantly over the last decade with the emergence of next-generation therapeutic antibodies. Conventional treatments like chemotherapy pose significant challenges, including adverse side effects. Monoclonal antibodies have paved the way for more targeted and effective interventions. The evolution from chimeric to humanized and fully human antibodies has led to a reduction in immunogenicity and enhanced tolerance in vivo. The advent of next-generation antibodies, including bispecific antibodies, nanobodies, antibody-drug conjugates, glyco-engineered antibodies, and antibody fragments, represents a leap forward in cancer therapy. These innovations offer increased potency, adaptability, and reduced drug resistance. Challenges such as target validation, immunogenicity, and high production costs exist. However, technological advancements in antibody engineering techniques provide optimism for addressing these issues. The future promises a paradigm shift, where ongoing research will propel these powerful antibodies to the forefront, revolutionizing the fight against cancer and creating new preventive and curative treatments. This review provides an overview of three next-generation antibody-based molecules, namely bispecific antibodies, antibody-drug conjugates, and nanobodies that have shown promising results in cancer treatment. It discusses the evolution of antibodies from conventional forms to next-generation molecules, along with their applications in cancer treatment, production methods, and associated challenges. The review aims to offer researchers insights into the evolving landscape of next-generation antibody-based cancer therapeutics and their potential to revolutionize treatment strategies.

Bispecific killer cell engagers employing species cross-reactive NKG2D binders redirect human and murine lymphocytes to ErbB2/HER2-positive malignancies

NKG2D is an activating receptor expressed by natural killer (NK) cells and other cytotoxic lymphocytes that plays a pivotal role in the elimination of neoplastic cells through recognition of different stress-induced cell surface ligands (NKG2DL). To employ this mechanism for cancer immunotherapy, we generated NKG2D-engaging bispecific antibodies that selectively redirect immune effector cells to cancer cells expressing the tumor-associated antigen ErbB2 (HER2). NKG2D-specific single chain fragment variable (scFv) antibodies cross-reactive toward the human and murine receptors were derived by consecutive immunization of chicken with the human and murine antigens, followed by stringent screening of a yeast surface display immune library. Four distinct species cross-reactive (sc) scFv domains were selected, and reformatted into a bispecific engager format by linking them via an IgG4 Fc domain to a second scFv fragment specific for ErbB2. The resulting molecules (termed scNKAB-ErbB2) were expressed as disulfide-linked homodimers, and demonstrated efficient binding to ErbB2-positive cancer cells as well as NKG2D-expressing primary human and murine lymphocytes, and NK-92 cells engineered with chimeric antigen receptors derived from human and murine NKG2D (termed hNKAR and mNKAR). Two of the scNKAB-ErbB2 molecules were found to compete with the natural NKG2D ligand MICA, while the other two engagers interacted with an epitope outside of the ligand binding site. Nevertheless, all four tested scNKAB-ErbB2 antibodies were similarly effective in redirecting the cytotoxic activity of primary human and murine lymphocytes as well as hNKAR-NK-92 and mNKAR-NK-92 cells to ErbB2-expressing targets, suggesting that further development of these species cross-reactive engager molecules for cancer immunotherapy is warranted.

Immune-inflammatory modulation by natural products derived from edible and medicinal herbs used in Chinese classical prescriptions

BACKGROUND

Edible and medicinal herbs1 (EMHs) refer to a class of substances with dual attribution of food and medicine. These substances are traditionally used as food and also listed in many international pharmacopoeias, including the European Pharmacopoeia, the United States Pharmacopoeia, and the Chinese Pharmacopoeia. Some classical formulas that are widely used in traditional Chinese medicine include a series of EMHs, which have been shown to be effective with obvious characteristics and advantages. Notably, these EMHs and Chinese classical prescriptions2 (CCPs) have also attracted attention in international herbal medicine research because of their low toxicity and high efficiency as well as the rich body of experience for their long-term clinical use.

PURPOSE

Our purpose is to explore the potential therapeutic effect of EMHs with immune-inflammatory modulation for the study of modern cancer drugs.

STUDY DESIGN

In the present study, we present a detailed account of some EMHs used in CCPs that have shown considerable research potential in studies exploring modern drugs with immune-inflammatory modulation.

METHODS

Approximately 500 publications in the past 30 years were collected from PubMed, Web of Science and ScienceDirect using the keywords, such as natural products, edible and medicinal herbs, Chinese medicine, classical prescription, immune-inflammatory, tumor microenvironment and some related synonyms. The active ingredients instead of herbal extracts or botanical mixtures were focused on and the research conducted over the past decade were discussed emphatically and analyzed comprehensively.

RESULTS

More than ten natural products derived from EMHs used in CCPs are discussed and their immune-inflammatory modulation activities, including enhancing antitumor immunity, regulating inflammatory signaling pathways, lowering the proportion of immunosuppressive cells, inhibiting the secretion of proinflammatory cytokines, immunosuppressive factors, and inflammatory mediators, are summarized.

CONCLUSION

Our findings demonstrate the immune-inflammatory modulating role of those EMHs used in CCPs and provide new ideas for cancer treatment in clinical settings.

A dual-targeting approach using a human bispecific antibody against the receptor-binding domain of the Middle East Respiratory Syndrome Coronavirus

The emergence of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) has posed a significant global health concern due to its severe respiratory illness and high fatality rate. Currently, despite the potential for resurgence, there are no specific treatments for MERS-CoV, and only supportive care is available. Our study aimed to address this therapeutic gap by developing a potent neutralizing bispecific antibody (bsAb) against MERS-CoV. Initially, we isolated four human monoclonal antibodies (mAbs) that specifically target the MERS-CoV receptor-binding domain (RBD) using phage display technology and an established human antibody library. Among these four selected mAbs, our intensive in vitro functional analyses showed that the MERS-CoV RBD-specific mAb K111.3 exhibited the most potent neutralizing activity against MERS-CoV pseudoviral infection and the molecular interaction between MERS-CoV RBD and human dipeptidyl peptidase 4. Consequently, we engineered a novel bsAb, K207.C, by utilizing K111.3 as the IgG base and fusing it with the single-chain variable fragment of its non-competing pair, K111.1. This engineered bsAb showed significantly enhanced neutralization potential against MERS-CoV compared to its parental mAb. These findings suggest that K207.C may serve as a potential candidate for effective MERS-CoV neutralization, further highlighting the promise of the bsAb dual-targeting approach in MERS-CoV neutralization.

Engineering a tumor-selective prodrug T-cell engager bispecific antibody for safer immunotherapy

T-cell engaging (TCE) bispecific antibodies are potent drugs that trigger the immune system to eliminate cancer cells, but administration can be accompanied by toxic side effects that limit dosing. TCEs function by binding to cell surface receptors on T cells, frequently CD3, with one arm of the bispecific antibody while the other arm binds to cell surface antigens on cancer cells. On-target, off-tumor toxicity can arise when the target antigen is also present on healthy cells. The toxicity of TCEs may be ameliorated through the use of pro-drug forms of the TCE, which are not fully functional until recruited to the tumor microenvironment. This can be accomplished by masking the anti-CD3 arm of the TCE with an autoinhibitory motif that is released by tumor-enriched proteases. Here, we solve the crystal structure of the antigen-binding fragment of a novel anti-CD3 antibody, E10, in complex with its epitope from CD3 and use this information to engineer a masked form of the antibody that can activate by the tumor-enriched protease matrix metalloproteinase 2 (MMP-2). We demonstrate with binding experiments and in vitro T-cell activation and killing assays that our designed prodrug TCE is capable of tumor-selective T-cell activity that is dependent upon MMP-2. Furthermore, we demonstrate that a similar masking strategy can be used to create a pro-drug form of the frequently used anti-CD3 antibody SP34. This study showcases an approach to developing immune-modulating therapeutics that prioritizes safety and has the potential to advance cancer immunotherapy treatment strategies.

Immunotherapy in Acute Myeloid Leukemia: A Literature Review of Emerging Strategies

In the last twenty years, we have witnessed a paradigm shift in the treatment and prognosis of acute myeloid leukemia (AML), thanks to the introduction of new efficient drugs or approaches to refine old therapies, such as Gemtuzumab Ozogamicin, CPX 3-5-1, hypomethylating agents, and Venetoclax, the optimization of conditioning regimens in allogeneic hematopoietic stem cell transplantation and the improvement of supportive care. However, the long-term survival of non-M3 and non-core binding factor-AML is still dismal. For this reason, the expectations for the recently developed immunotherapies, such as antibody-based therapy, checkpoint inhibitors, and chimeric antigen receptor strategies, successfully tested in other hematologic malignancies, were very high. The inherent characteristics of AML blasts hampered the development of these treatments, and the path of immunotherapy in AML has been bumpy. Herein, we provide a detailed review of potential antigenic targets, available data from pre-clinical and clinical trials, and future directions of immunotherapies in AML.

Diagnostic Flow Cytometry in the Era of Targeted Therapies: Lessons from Therapeutic Monoclonal Antibodies and Chimeric Antigen Receptor T-cell Adoptive Immunotherapy

Therapeutic monoclonal antibodies (therapeutic mAb) and adoptive immunotherapy have become increasingly more common in the treatment of hematolymphoid neoplasms, with practical implications for diagnostic flow cytometry. Their use can reduce the sensitivity of flow cytometry for populations of interest owing to downregulation/loss of the target antigen, competition for the target antigen, or lineage switch. Expanded flow panels, marker redundancy, and exhaustive gating strategies can overcome this limitation. Therapeutic mAb have been reported to cause pseudo-light chain restriction, and awareness of this potential artifact is key. Established guidelines do not yet exist for antigen expression by flow cytometry for therapeutic purposes.

SOHO State of the Art Updates and Next Questions | Optimal Timing of Blinatumomab for the Treatment of B-Acute Lymphoblastic Leukemia

Blinatumomab is a CD19 targeting bi-specific T-cell engager antibody construct developed for the treatment of CD19 expressing B-cell malignancies. Numerous adult and pediatric B-ALL clinical trials have demonstrated blinatumomab's efficacy in the relapse setting as well as in patients with residual disease after upfront chemotherapy. The safety profile of blinatumomab is also favorable, making it a feasible option for most patients. Several key questions remain, including the role of blinatumomab as a replacement for toxic elements of standard chemotherapy regimens in the upfront setting, its role as a bridge to hematopoietic stem cell transplantation, or whether previous blinatumomab impacts the efficacy of subsequent CAR-T cell therapy.